The present invention generally relates to medical methods and devices, and in certain of its embodiments to methods and devices useful to reduce lung volume.
Chronic obstructive pulmonary disease (“COPD”) refers to chronic bronchitis and emphysema, a pair of two commonly co-existing diseases of the lungs in which the airways become narrowed. This leads to a limitation of the flow of air to and from the lungs causing shortness of breath. In contrast to asthma, the limitation of airflow is poorly reversible and usually gets progressively worse over time. COPD is caused by noxious particles or gas, most commonly from tobacco smoking, which triggers an abnormal inflammatory response in the lung. The inflammatory response in the larger airways is known as chronic bronchitis, which is diagnosed clinically when people regularly cough up sputum. In the alveoli, the inflammatory response causes destruction of the tissues of the lung, a process known as emphysema. The natural course of COPD is characterized by occasional sudden worsenings of symptoms called acute exacerbations.
Surgery is sometimes helpful for certain COPD and emphysema patients. A bullectomy is the surgical removal of a bulla, a large air-filled space that can compress the surrounding, more normal lung. In lung volume reduction surgery, parts of the lung that are particularly damaged by emphysema are removed allowing the remaining, relatively good lung to expand and work better. Conventional lung reduction surgery involves surgical resection of the most severely affected areas of emphysematous, non-bullous lung. This is a surgical option involving a mini-thoracotomy for patients suffering end stage COPD due to underlying emphysema, and has been reported to improve lung elastic recoil as well as diaphragmatic function.
Conventional lung reduction surgery is, however, traumatic. The surgery is different than other surgeries in that it should not be considered a single procedure. There is an extensive pre- and post-operative rehabilitation program which needs to be followed for maximal effect. Some general surgery complications include: fever, wound infections, wound hematomas, postoperative fatigue, and tachycardia. The main complication of lung volume reduction surgery is an air leak. Normally there is a vacuum between the ribs and the lungs which helps to make the lungs expand and fill with air when the chest wall expands. If an air leak allows air in the potential space between the ribs and lungs then the vacuum effect is gone and the lung sags. This makes it very difficult to inflate the lungs and perform gas exchange. For these reasons, it is desirable to provide improved and/or alternative methods and devices for performing lung volume reduction.